Recent work has identified relationships between certain telencephalic brain structures (notably hippocampus and frontal cortex) and specific aspects of olfactory learning and memory in adult rats: moreover, links have been established between brain rhythms associated with sniffing and the cellular mechanisms that produce long-term potentiation of synapses. The proposed work will test and extend these ideas by identifying developmental times at which various features of adult-like learning appear and comparing with the ages at which lesions to specific brain structures begin to disrupt behavior. Similar comparisons will be made with the maturation of the individual cellular events that produce the synaptic potentiation effect. Attempts will also be made to analyze the links between certain early forms of odor learning described by other researchers with successive discrimination learning in the adult (i.e., do neonatal learning systems play a role in adult learning and if so, is their role in series or parallel to those of later maturing structures?). The results should considerably expand our understanding of the locus and contributions of learning systems in the olfactory forebrain and provide insights into their relationships with learning processes found early in life.